Congress has mandated that the Department of Defense perform screening for concussion, or mild traumatic brain injury, on all service members redeploying from Iraq and Afghanistan. However, the retrospective diagnosis of concussion is complicated by the subjective nature of the complaints, overlap of symptoms with other conditions, and the normally rapid recovery of neurocognitive function following a concussive event. One diagnostic and screening test in current use by the Department of Defense is the Automated Neuropsychological Assessment Metrics (ANAM). A team of researchers deployed to Iraq between January and April 2009 to test the validity of the ANAM for the diagnosis of concussion in the combat environment. Performance by concussed participants on all six ANAM subtests was compared with that of controls. The ANAM appears to have no utility as an individual diagnostic or population screening tool for the detection of neurocognitive dysfunction from a single, uncomplicated concussion when administered 10 or more days following injury. Further studies are required to determine the modalities providing optimal sensitivity and specificity for use as diagnostic or screening tests beyond the first 72-hour acute postinjury period.